1. Field of the Invention
The present invention is related to a stacked monopole antenna for broadband communication equipment, and especially to a miniaturized stacked antenna having excellent gain and feature of broadband.
2. Description of the Prior Art
The industry of communication equipment keeps on stably developing in the recent years following fast growth of the markets of electric communication, particularly the markets of mobile phones. By virtue that requirement on the multi-frequency mobile phones increases rapidly, the antennas for such communication equipments thereby are supposed to be able to operate with more than two frequencies.
At the same time, volumes of modern mobile phones are largely reduced, this makes a huge pressure to promote miniaturization of antennas; and this is because mainly of the fact that the miniaturization of antennas will render the gains and bandwidths of the antennas limited.
In order to miniaturize antennas and to hide antennas with small lengths in mobile phones, it has been the inevitable tendency that built-in antennas with reduced volumes are used to substitute for exposed helix antennas. When it is desired to hide such a miniaturized antenna in a communication equipment, designing for the antenna shall include the factors of: ability of generating a broadband, ability of easy impedance matching with a feed-in line and having reduced volume; however, a broadband antenna now available evidently is hard to meet the requirement of the designing nor to have a good function of receiving and emitting signal.